This invention relates to the manufacture of bowling balls and, more specifically, to high performance bowling balls. Because a bowling ball must necessarily be of a certain diameter, hardness, and resiliency to satisfy the requirements of the American Bowling Congress and must also have the capacity of withstanding repeated inertial shocks without cracking, fracturing, or denting, bowling balls are typically manufactured to be solid throughout. Compliance with the American Bowling Congress Bowling Ball Specifications (hereinafter referred to as "A.B.C. Specifications") is of vital commercial importance because only complying balls may be used in the majority of bowling tournaments held in the United States. A copy of the Aug. 1, 1976 A.B.C. Specifications, which specifications are still current, is attached hereto as Exhibit "A".
One or more inner cores or shells may be used within the bowling ball. The inner core is typically comprised of materials of various densities, such as sawdust, barium sulfate and different concrete-like materials. The densities of these materials generally range from about 0.12 g/ml to 5.0 g/ml. The overall density of the inner core is adjusted by varying the ratio of high and low density materials.
The typical bowling ball containing conventional materials and manufactured using conventional methods has an outermost layer comprised of an essentially homogeneous material, such as rubber or polyester resin having a density ranging from 1.1 to 1.3 g/ml.